I don’t think 100 mg of primo will do much of anything unless you have Mr. Olympia genetics, or run it for at least 6 months.
I am asking for debate from a few regular posters here who I don’t see eye to eye with regarding 5 ar inhibitors, but I’d suggest you at least look into that if hair loss is a concern.
Not too long ago I wrote a bunch of replies in a finasteride (one of the two main 5 ar drugs) thread. You can read through that here to get both sides.